Download 4.5 - Isosceles and Equilateral Triangles.notebook

4.5 ­ Isosceles and Equilateral Triangles.notebook
Day 6: Isosceles & Equilateral Triangles
November 21, 2016
Date: 11/21
Isosceles Triangles
THEOREM 4­3: ISOSCELES TRIANGLES THEOREM:
If two sides of a triangle are congruent,
then the angles opposite those sides
are congruent.
THOEREM 4­4: CONVERSE OF THE ISOSCELES TRIANGLE THEOREM
If two angles of a triangle are congruent,
then sides opposite those angles
are congruent.
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
Ex 1) a). Is GH = HK? Explain.
b). Is HL = KJ? Explain.
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
THEOREM 4­5:
If a line bisects the vertex angle
of an isosceles triangle, then the line is also the
perpendicular bisector of the base.
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
Ex 2). What is the value of x?
a)
b)
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
EQUILATERAL & EQUIANGULAR TRIANGLES
COROLLARY TO THEOREM 4­3:
If a triangle is equilateral, then
the triangle is equiangular.
COROLLARY TO THEOREM 4­4:
If a triangle is equiangular, then
the triangle is equilateral.
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
Ex 3). What is the value of x and y?
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
Ex 4). Complete each statement:
a)
b)
c)
d)
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
Ex 5). Find each measure
a)
b)
c)
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4.5 ­ Isosceles and Equilateral Triangles.notebook
November 21, 2016
Homework:
pg. 269 #1 – 12, 15 – 18, 21
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